LAUSR

Techniques for wireless energy harvesting (WEH) are being emerged as a fascinating set of solutions to extend the lifetime of energy-constrained wireless networks. They are commonly regarded as a key functional technique for almost perpetual communications. With the WEH technology, wireless devices are able to harvest energy from, e.g., different light sources or RF signals broadcast by ambient/dedicated wireless transmitters to support their operation and communications capabilities. The WEH technology will have increasingly wider range of use in upcoming applications for, e.g., wireless sensor networks, machine-to-machine (M2M) communications, and the Internet of Things (IoT). In this paper, the usability and fundamental limits of solar cell or photovoltaic harvesting-based M2M communication systems are studied and presented. The derived theoretical bounds are in essence based on the Shannon capacity theorem, combined with selected propagation loss models, assumed additional link nonidealities, as well as the given energy harvesting and storage capabilities. Fundamental performance limits and available capacity of the communicating link are derived and analyzed, together with extensive numerical results evaluated in different practical scenarios, including realistic implementation losses and the state-of-the-art printed supercapacitor performances. In particular, low-power sensor-type communication applications using passive wake-up radio (WuR)-assisted operation are addressed in this paper. The results show the benefits of using passive WuR, especially when the number of nodes is small. Moreover, the presented analysis principles and results establish clear feasibility regions and performance bounds for WEH-based low rate M2M communications in the future IoT networks.